Processor stays in energy-saving mode (multiplier stays low) [ Edited ]

[R-JW]

I have a HP Compaq 8510w (laptop) with a Intel Core 2 Duo T9300., running Windows 7

The problem:

I have had preformance problems for a long time now (a few months at least) and I just found out (part of) the reason.

The processor stays in low preformance (energy saving) mode and is unable to go back.

Resulting in me using a 800 MHz processor.

This has been found / confirmed by: MS Resource Monitor, CPU-Z and  Core Temp. 

The pc works ..., but everything that uses some processor power is slow.

For now I suspect it to be some bug in the Windows 7 power managment, a driver or the BIOS.

If anyone knows about a reason for this behavior, please tell me.

What I've done / checked

With result:

- Restart [cpu speed and multiplier changes back to normal, temporary]  

- Changing the 'processor state' in the advanced power options:

setting both minimum states to 99% to prevent the multiplier from being lowered

result: when on external power, the multiplier stays 12.5

But, when the pc is on its battery it lowers the multiplier too 4, and slows the fan, even when I'm running Prime95.

(btw. when I set the minimum state to 100%, cpu-z and core temp report the multiplier being 13.5 when the cpu is idle) 

edit (0:20 04-11): for now this seems to work. When I have the pc on battery for a few minutes, it takes long (about 10 min) before it returns to full speed, but it comes back. 

Without result:

Spoiler

- removed McAfee (I originally blamed it for the 100% proc. usage), [currently using MS Security Essentials]

- Virus checks, spyware checks, disc defrag, Windows update, driver updates [nothing]

- Reset the BIOS settings [no difference form a normal restart, it still happens]

Windows power settings 

While bugged:

- Changing too HP-optimized 'power plan'  [nothing]

- Changing the minimum and maximum 'processor state' in the advanced power options [nothing, stays 800MHz] 

- Running prime95 [nothing, still 800MHz] 

While working OK

- Changing 'processsor state' [perfect and immediate reaction to changes]

- Reactions to use seems normal: the multiplier is 4 if nothing is happening, than 6, 10,  ... till 12.5 under load.

- Running prime95, constant 2.5 GHz

Using Sleep modus (with power settings forced high multiplier) [nothing, muliplier stays high over sleep session] 

To try

- Using Hibernate (I normally hibernate my pc overnight)

- Try a harddrive with a fresh windows install. 

System Details

Spoiler

The default speed for my T9300 is 2.5 GHz using a multiplier of 12.5 (fsb is 200 MHz)

The lowest speed is 800 MHz (multiplier = 4) 

Windows 7 Ultimate x64 (fully updated)

Bios version: ...

HP updates

- System Default Settings for MS Win 7 v2.2 (2011-06-07)   

- Intel AMT Driver v2.6.10.1043 (2009-11-09)

- Intel Pro/Wireless Drivers for MS W7 v13.0 (2009-12-14)

- Intel ProSet Extensions for MS W7 v13.0 (2009-10-22)

- nVidia Graphincs Driver for MS W7 186.24 (2009-10-19) [incorrect from windows updates I have v261.28] 

- Essential System Updates for MS W7 v1.0 (2010-01-19)

[R-JW]

I still don't know the reason or a fix for this issue, but I know now when it happens.

When I hibernate the laptop while it is running on it's battery!

When the laptop is running on its battery it always lowers the multiplier (max-clock-speed).
And when it goes into hibernation mode it apparently saves this as the maximum multiplier, resulting in an underclocked cpu.

To me this sounds like a 'bios / Windows 7 hybernate" issue.

I'm not sure what to do about it. For now I've switched to using the sleep mode at night and, when I'll have to travel, being very carefull not to unplug it before before it's finished hibernating.
I'll still try to update the dirvers etc when they are available. When this'll be fixed I'll try to update this topic.

[Hat69]

I am having the same problem with an odd difference ..

The multiplier gets stuck on 8 resulting in a whopping speed of 800 MHz and the delightful resultant hangs & hiccups etc .. whever I connect the AC cord after it had been running on battery.

I tried all of the above solutions too, but the only thing that seems to work is a restart while the power cord is still plugged in, if I disconnect it there are no issues but if I do reconnect it, it goes down back to a multiplier of 8 & stays there.

Any help on the matter would be greatly appreciated.

Forgot to mention that I have an amd A8-3520M processor, so whatever the bug mentioned above affects both intel & amd

[nukamendi]

Try getting a more powerful ac adapter/charger, i had the same problem with a core i7 that stuck in energy save mode because i changed the adapter but the first one i got, was a 95w with less amperage than the processor needed, i solved it getting a 120w with 2.5 ampers . GL